Photosynthetic gas exchange and chlorophyll in Bambara groundnut (Vigna subterranea l. Verdc.) subjected to water deficit

The study evaluated the response of two Bambara groundnut (Vigna subterranea L. Verdc.) landraces sourced from contrasting environments to periods of water deficit initiated at vegetative stage. The two landraces AHM-753 and Bogor, from Namibia and Indonesia, respectively, were grown in pots and irrigation was withheld 30 days after sowing in stressed group while the control plants were fully watered. The responses were studied by measurements of relative water content (RWC), photosynthetic gas exchange, and SPAD chlorophyll. RWCand gas exchange parameters were found to decrease in stressed plants. Significant (P<0.001) decrease in SPAD chlorophyll concentration was seen only in Bogor landrace. The results showed a possible drought avoidance strategy in Bambara groundnut in response to water deficit. The results pointed a greater tolerance to the imposed drought in the landrace AHM-753 compared to Bogor suggesting that the origin of the landrace and the environment it is adapted to determine its response to water deficit.